Dr Sophie Lund Rasmussen at microscope (IMAGE) University of Oxford Caption Dr Sophie Lund Rasmussen looks in the microscope to count year rings in a section of a hedgehog jawbone to determine the age of the hedgehog. Credit: Thomas Degner. Credit Dr Sophie Lund Rasmussen looks in the microscope to count year rings in a section of a hedgehog jawbone to determine the age of the hedgehog. Credit: Thomas Degner. Usage Restrictions The image can only be used if credited License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.